TR 7 Cooling Temp Gauge

[Neil_W]

A small problem but need some advice for peace of mind

 

The Car had a new Water Pump & System pressure test for Cyl head last year ( Head ok ) & then the temp gauge sat at 1/4 so that was fine which was in Late Summer.

 

Anti freeze is nice & blue with measured at -20 deg range.

I did have a top up coolant with 100 ml of neat Anti freeze to 1 inch below neck of expansion tank last week as thermostat gasket had leaked.

 

After the winter & a run yesterday the gauge is now sitting at 1/8 so running quite cool or gauge is wrong.

 

I fitted a new Thermostat as had a new one in garage & temp gauge still the same.

 

Have ordered a new temp transmitter as a cheap part to see if that helps.

 

How do you test the Temp gauge ( full range C -H ) apart from putting sensor in a cup of boiling water ?

Remember on an old Ford that earthing the sensor wire made the gauge go to hot - is this the same on TR7 ?

Is Anti Freeze too strong which is lowering the temp ?

 

Had engine running in the drive for 30 mins & temp stayed at 1/8 then when stopped dropped slowly to 0.

 

When running the following is felt:

Inlet manifold hot, top cooling hose pressurised, top of radiator hot, bottom of radiator cool,bottom radiator hose slightly pressurised & cool, expansion tank warm & no water leaks.

So have a feeling all is ok on that front - just the gauge that is staring me in the face when driving - watch this more than the speedo ( at least not sitting at hot )

 

Whew - above a bit long winded but any thoughts

 

Neil